Quick Links

What is this stuff? Fill in the grid. Once the perimeter and the long interior beams are installed, shorter pieces are cut and fit in between. A compact laser projects the layout marks across the entire ceiling so that the beams are placed straight. Made from high-density expanded polystyrene (EPS), foam moldings like those used in this project have their origins in the architec tural details found on synthetic-stucco exteriors. But instead of a fiberglass mesh that accepts acrylic stucco, the moldings made for inte rior use are coated at the factory with a thin layer of joint compound. Inside corners are mitered on-site rather than coped, and seams where the lengths of molding come together use butt joints rather than scarf joints. Corners are caulked, and gaps and seams are filled with compound and sanded with 220-grit paper when dry. Suppliers of foam moldings, who usually cater to the syntheticstucco and drywall trades, have large catalogs of stock profiles and can make custom profiles subject to minimum order. Common profiles cost from $3 to $6 (U.S.) per ft. adhe sive to act as a backer for the lightweight joint compound we apply to the seams and gaps. The moldings come with all of the visible surfaces coated with compound, and they accept paint like drywall. The finished product is often mistaken for painted wood. Because the EPS is very stable, it doesn’t move with changes in humidity and temperature, so the joints stay tight during our humid summers and cold winters. 40 FINE HOMEBUILDING Why would a homeowner or builder choose to install a coffered ceiling or crown molding made from EPS and joint compound instead of wood or MDF? The answer is simple: speed and cost. With a crew of three, we installed the coffered ceiling shown here in half a day. Caulking all the gaps and inside corners took another two hours. The material cost $1400 (U.S.), a fraction of what it would cost a finish carpenter to install a similar ceiling made from wood moldings. The only downside we see is that the moldings only come in 8-ft. lengths, so you end up making more cuts and filling more seams than you would with longer material. □ Brian Kitchin and Nick Aitchison are the owners of Drywall Nation in Sudbury, Ont., and are Fine Homebuilding ambassadors. Photos by Patrick McCombe.